大晶粒纯镁疲劳变形过程中交叉滑移迹线的分析

Criss-cross Slip Traces During the Cyclic Deformation of Pure Coarse-Grained Polycrystalline Magnesium

摘要:

在室温条件下研究了大晶粒纯镁疲劳变形过程中有可能激活的滑移系统及滑移迹线。结果表明，经过疲劳变形后大量的纵横交叉滑移迹线在样品表面产生，基于晶粒取向与滑移迹线方向的综合判定，这种纵横交叉滑移迹线是由反复疲劳变形过程中基体的基面滑移与同一区域内｛102｝孪生过程中所再次产生的基面滑移而形成。通过实验观察到最有可能发生的锥面滑移系统为在｛101｝面上所产生的<113>锥面滑移，但总体上来说，基面的滑移迹线比锥面的滑移迹线更密集，这说明锥面滑移在整个疲劳变形过程中被抑制。

Abstract:

The possible activated slip systems and slip traces of pure coarse-grained magnesium were investigated during cyclic deformation at room temperature. Results show that numerous criss-cross slip traces are observed on the surface of the specimens after cyclic loading. Based on the results of a combinatory analysis for the unit cell orientation and direction of the slip traces, it is determined that the criss-cross slip traces are formed by the intersection of the basal slip traces in the former matrix and the subsequent {} twinning area during the reversed cyclic loading. Moreover, the most likely pyramidal slip mode is the sliding of <> pyramidal dislocations on {} pyramidal planes, while the basal slip traces are denser than the pyramidal slip traces, suggesting that there is limited pyramidal slip activity.